The present invention relates to a room temperature-curable organopolysiloxane composition or, more particularly, to a room temperature-curable organopolysiloxane composition curable by the dealcoholation reaction for crosslinking and having excellent stability in storage over a long period of time.
Various types of room temperature-curable organopolysiloxane compositions are known and widely used in applications, of which the dealcoholation type compositions are advantageously used in electric and electronic industries due to the absence of corrosive ingredients and emission of irritant gases because the room temperature-curable organopolysiloxane composition of this type is formulated with a diorganopolysiloxane terminated at both molecular chain ends each with a silanolic hydroxy group as the main ingredient together with an alkoxysilane compound, e.g. methyl trimethoxy silane, as the crosslinking agent and a catalyst compound such as organic titanium compounds and organic titanium-containing chelate compounds so that the crosslinking reaction therein to give a rubbery cured material proceeds by the condensation reaction between the silanol groups and the alkoxy groups to produce an alcoholic compound as the condensation product.
On the contrary to the above mentioned advantages, the dealcoholation type room temperature-curable organopolysiloxane composition, referred to as a RTV composition hereinafter, has several problems and disadvantages. For example, the velocity of curing thereof is relatively low, especially, in the core portion of a thick body and the stability of the composition in storage is poor eventually to cause troubles in use relative to the curability.
Several proposals and attempts have been made in order to improve the dealcoholation type RTV composition in this regard including a method of admixing the composition with a silane compound having two alkoxy groups as a so-called "silane scavenger" to improve the storage stability and curability. This method, however, is disadvantageous because such a special silane compound must be prepared separately for this particular purpose and, while the silane compound has other highly reactive hydrolyzable groups than the alkoxy groups such as amido and amino groups to cause corrosiveness or unpleasant odor, silane compounds having these groups cannot be used as an adhesive in electric and electronic industries.